The long term objective of the proposed Clinical Research Center is to develop improved assessment and rehabilitation procedures for individuals with speech disorders of neurologic origin. Research is to be conducted in three major areas, each of which contributes information on the normal or abnormal neuromotor control of speech. (1) Research on normal mechanisms includes studies of the maturation of speech motor control in normal children and of regulatory systems in the normal adult. (2) Kinesiologic studies of abnormal mechanisms are designed to reveal the nature of the speech motor problems that accompany neurologic disorders affecting different motor centers of the nervous system. (3) Experiments in speech rehabilitation will focus on the (a) efficacy of biofeedback with selected individuals, and (b) prosthetic management of the velopharynx in various neurologic conditions. The methods used to study neuromotor control in all three of these areas include recordings of the acoustic speech signal, structural movements, aerodynamic variables, and muscle action potentials. The data collected from normally developing children, normal adults, and adult neurologic subjects will be used to form hypotheses and experimental designs for the study of neurological speech disorders in children.